Hinged mounting for tilt cab

ABSTRACT

A tilt cab is mounted at one end of a vehicle for downward tilting movement around a pivot axis and subsequent support on a lift member associated with the vehicle. A load damping and energy storing device is connected between the cab and the frame of the vehicle in such a manner as to be activated by upward movement of the lift member conjointly with the downward swinging of the tilt cab, to first dampen the movement of the tilt cab downwardly while simultaneously being loaded and thereafter exerting a hold-down force on said tilt cab to maintain secure shake-proof support of the cab on the lift member.

[ 1 June5,1973

[54] HINGED MOUNTING FOR TILT CAB [75] Inventor: Walter Hirsch, DonMills, Ontario,

Canada [73] Assignee: Massey-ferguson Industries Limited,

Toronto, Ontario, Canada 22 Filed: Oct.12,1971

21 Appl.No.: 188,067

[52] US. Cl. ..296/28 C, 180/89 A [51] Int. Cl. ..B62d 33/06 [58] Fieldof Search ..296/28 C, 35 R; 180/89 A [56] References Cited UNITED STATESPATENTS 2,947,376 8/1960 Norrie ..l80/89 3,005,511 10/1961 Riedy 180/89FOREIGN PATENTS OR APPLICATIONS 1,275,884 8/1968 Germany ..296/35 RPrimary Examiner-Leo Friaglia Assistant ExaminerJohn A. PekarAttorney-Gerhardt, Greenlee & Farris [5 7] ABSTRACT A tilt cab ismounted at one end of a vehicle for downward tilting movement around apivot axis and subsequent support on a lift member associated with thevehicle. A load damping and energy storing device is connected betweenthe cab and the frame of the vehicle in such a manner as to be activatedby upward movement of the lift member conjointly with the downwardswinging of the tilt cab, to first dampen the movement of the tilt cabdownwardly while simultaneously being loaded and thereafter exerting aholddown force on said tilt cab to maintain secure shakeproof support ofthe cab on the lift member.

6 Claims, 4 Drawing Figures INVENTOR. 7 2 WALTER HIRSCH 4 TTORNEYS.

PATENTEDJUH 5 I975 SHEET 2 UF 2 INVENTOR.

WALTER HIRSCH Mull.

A TTOR/VfYS.

I HINGED MOUNTING FOR TILT CAB BACKGROUND AND SUMMARY OF INVENTION Thepresent invention relates to supporting mechanism for tilt cabs forvehicles and more in particular to a combined self-acting, load dampingand hold-down mechanism for a tilt cab.

It has been known to provide vehicles which are equipped with anunder-the-cab engine, with tilting cabs to permit easy and unobstructiveaccess to the engine compartment of the vehicle. Such arrangements arequite common in heavy truck vehicles having the engine mounted above orbehind the front axle.

It is also known to provide construction machines or other heavyequipment such as agricultural vehicles, which normally have an openoperators platform, with removable cab enclosures for protection of theoperator and the operating controls on the platform against the weather.

As is known, construction machines and agricultural machines are ofgenerally large dimensions and sometimes of excessive height which onthe construction site or open field terrain on which these machinesoperate normally causes no problems. However, these heavy machines haveto be periodically transported from one area of operation to another viathe road or railway by being placed on flattop trailers or railway cars.

During over-the-road or railroad transportation the height of thesemachines becomes critical in view of possible obstructions along theroad or railway, particularly tunnels or overpasses which have definedmaximum clearance dimensions. Thus, in order to clear overpasses,tunnels or other obstructions along the road or railway, or to move themachine into a building, in many instances, has to be removed entirelyprior to transport of the machine. This requires tedious and timeconsuming disassembly of the cab from the machine and subsequentreassembly at the point of destination.

It has been proposed herebefore to provide the cab with a tiltingmechanism which permits the cab to remain on the machine by merelyswinging the cab from its normal upright position downwardly towards theside or front of the machine. However, due to the extreme height of theoperators platform relative to the ground serious difficulties have beenencountered herebefore in securely supporting the cab in its downwardswinging position. This difficulty is further amplified by the extremeremote location of the center of gravity of the cab relative to thepivot of the cab.

Herebefore hydraulic or other fluid mechanisms have been proposed forswinging movement of the cab downwardly upon a suitable support withoutsubmitting the cab to impact or shock loads. These known mechanisms arecostly and require additional fluid controls and fluid power lineinstallations. Additionally, they may interfere with other machinecomponents and at best are difficult to accommodate in existing machinestructures.

An additional problem resides in securely retaining the tilted cab onthe cab support during transport of the machine from one location toanother so as to prevent the tilted cab from shaking and rattling whichultimately results in damage to the cab and cab support.

In known tilt cab mechanism of this type, the cab had to be manuallysecured onto the support by hold-down means-at added costs of theadditional components and increased time and labor-in preparing themachine for transport over the road or rail.

In order to overcome the above mentioned drawbacks, the presentinvention provides improved mechanical means to effectively support thecab during tilting movement and to resiliently absorb any shock loadsassociated with the tilting movement. Thereafter, the same mechanicalmeans are effectively utilized to securely hold the cab down upon thesupport to prevent the cab from shaking and rattling during transport.

Accordingly, it is the primary object of the present invention toprovide improved cab support and holddown means for a tilting c'ab whichis completely mechanical and self-acting, inexpensive to manufacture andto install and requiring no fluid line and fluid control installations.

It is another object of the present invention to provide improved loadsupporting and resilient shock absorbing means for a tilt cap mechanism,while at the same time functioning as an effective hold-down means forthe tilted cab.

A further object of the present invention resides in the provision ofresilient load damping and shock absorbing means for a tilt cabmechanism which additionally functions as an energy storing device forsubsequent use as a hold-down means.

The above objects and other novel features of the present invention willbecome fully apparent by reference to the following detailed descriptionof a preferred embodiment thereof and when read in conjunction with theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate apreferred embodiment of the invention in which:

FIG. 1 is a fragmentary illustration of the front portion of anagricultural machine such as a combine showing the tilt cab of thepresent invention in its normal upright position; I

FIG. 2 is a similar fragmentary illustration of the front end of anagricultural vehicle showing the tilt cab in swung-down position upon asupport associated with the vehicle;

FIG. 3 is enlarged fragmentary cross-section through a frame portion ofthe front end of the machine illustrated in FIG. 1 and showing thepresent improved tilt cab load support and hold-down mechanism, more indetail. And FIG. 4 is a top plan view of the mechanism shown in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION With continuing reference to thedrawings, FIG. 1 schematically illustrates the front end of anagricultural machine 10 such as a combine or the like.

The combine or other machine 10 includes a body or frame 12 including anelevated platform 14 at the extreme forward end of the machine. Theplatform 14 defines an operators station 16 accessible by mans of aladder 18. The combine or other machine 10 as will be understood issupported by means of ground engaging wheels 20 (only one of which isshown) for travel over the ground.

Normally, the combine 10 or other machine is adapted to carry animplement 22 forwardly thereof which in operation of the machine .10will be detachably secured to a combined hitch and elevator mechanism24. Elevator 24 is pivotally supported on frame 12 as indicated at 26for selective raising or lowering movement of elevator 24 relative tothe ground by means of extendable links 28. Extendable links 28, whichmay be fluid motors or the like, are pivoted at one end to the machineand at their other end to elevator 24.

In the present instance, the operators station during operation of themachine 10 is enclosed by means of a cab 30 supported on the platform14. The cab 30 has a front end 32 and a top 34 which extends asubstantial distance H above the top of the combine or other machine 10when the cab is in normal upright position as shown in FIG. 1.

As is known, the machine 10 such as a combine or the like is adapted fornormal self-propelled operating movement over a field terrain but has tobe periodically transported to different locations by means ofover-theroad or railway carriers. In order to load the machine 10 ontothe carrier platform the implement 22 is detached from the elevator 24.Although the flat bed carriers for the machine 10 are usually designedto have a height level relative to the ground over which they travel topermit free passage of the relatively high super structure of themachine 10 under any obstructions such as overpasses bridges or tunnelsalong the road or railway, no allowance was made for the cab 30 which,in normal position, extends above the super structure of the machine 10.Thus, in many instances, the cab 30 cannot pass through the designedclearance heights of overpasses or tunnels along the road or railway andtherefore had to be removed from the machine 10 prior to transport.

In accordance with the present invention, and with additional referenceto FIG. 3 and 4, the cab 30 is pivotally attached to the platform 14 atthe lower front end by means of a pivot shaft 36 to thereby permit thecab 30 to be swung forwardly and downwardly around the pivot shaft 36 asshown in FIG. 2. This reduces the overall height of the machine 10 topermit clearance through obstacles such as overpasses and tunnels.

With particular reference to FIG. 3 and 4 the platform 14 is composed ofa frame assembly 15 having opposite side members 17 and 19 which areinterconnected by a crossframe member 21.

The lower front end of cab 30 is provided with a downward extensioncomprised of opposite side members 38 and 40 respectively which straddlethe front section of platform 14 outwardly of the side members 17 and 19as most clearly shown in FIG. 4.

Side frame members 17 and 19 of platform 14 are inwardly provided withcoaxially aligned boss portions 42 and 44 which each retain a bushing 46and 48. Bushings 46 and 48 are provided to rotatively support pivotshaft 36 within the frame 15 of platform 14 for extension outwardlythrough both side frame members 17 and 19. The outer ends of pivot shaft36 are received within cylindrical boss portions 50 and 52 secured tothe outside of side members 38 and 40 of the lower cab extension. Theouter ends of pivot shaft 36 are secured within their respective bossportions 50 and 52 by means of keys or the like (not shown) so that uponrotation of pivot shaft 36 within bushings 46, 48 cab 30 will be swungaround the axis of the pivot shaft between a normal upright positionshown in FIG. land the tilted position shown in FIG. 2.

It shall be mentioned here that the cab 30 may weight around 500 poundsand has a center of gravity extremely remote from the axis of pivotshaft 36 so that upon tilting movement of the cab 30 forwardly anddownwardly around pivot shaft 36, load absorbing and damping means arerequired for smooth movement and to prevent impact of the cab on itssupport.

In accordance with the invention, pivot shaft 36 is adapted to berotated for tilting movement of cab 30 by means of a lever 54 which iskeyed or otherwise secured to pivot shaft 36. Lever 54 radially extendsfrom pivot shaft 36 and its end is pivotally attached by means of a yokemember 56 and pivot pin 58 to a rigid rod 60. Rod 60 extends downwardlytowards elevator 24 to which the other end of rod 60 is pivotallyattached as seen at 62 in FIG. 1 and 2. Rod 60 is movable longitudinallywith swinging movement of elevator 24 for rotation of pivot shaft 36 ashereafter more thoroughly explained.

A second layer 64 is attached to pivot shaft 36 for rotation therewithwithin the confines of side frame members l7 and 19. Second lever 64 isangularly offset from lever 54 and is bifurcated to receive a pivotblock 66 pivotally secured to the lower end of lever 64 by means of pin68.

It shall be noted here that levers 54 and 64 are substantially equallength such that-the respective pivots' 58, 68 are moved along a commonarc described around the axis of pivot shaft 36 for a purpose to bedescribed hereafter.

Pivot block 66 of lever 64 is adapted to support one end of a pair ofrods 70 and 72 disposed adjacent to each other and in parallelrelationship for extension rearwardly from lever 64. The rearends ofrods 70, 72 extend slidingly through a rear pivot block 74 which ispivotally retained by means of aligned trunnions 76, 78 within the lowerends of a bracket 80 fastened to the frame of platform 14 rearwardly ofshaft 36. Rods 70, 72 are conjointly slidable within pivot block 74 fora purpose to appear hereafter.

Each of the rods 70, 72 supports a compression spring 82 and 84respectively of identical length. One end of each of the compressionsprings, 82, 84 is anchored'to the rear pivot block 74 whereas theopposite ends of the springs-opposite from pivot block 66remainunattached. It will be noted that in the normal inplace position of thecab 30 (FIG. 1) and as shown in solid lines in FIG. 3, the free ends ofcompression springs 82, 84 are a distance apart from pivot block 66 sothat under normal operating conditions of cab 30 springs 82, 84 remainunloaded in freely expanded position.

In the present instance, springs 82-84 have identical spring forcecharacteristics. However, it will be understood that a single spring maybe employed or any number of springs depending on the weight of the caband location of its center of gravity relative to its pivot point.

In operation of the device of the present invention, in order to swingcab 30 forwardly and downwardly on machine 10, elevator 24 is actuatedfor upward swinging movement around its pivot 26 by means of fluidmotors 28. Upward movement of elevator 24 causes similar upward movementof rod 60 which is attached to elevator 24 at pivot point 62.Longitudinal upward movement of rod 60 causes angular displacement oflever 54 to thereby rotate pivot shaft 36 in counterclockwise direction(in the drawings) by means of attachment of the lower front endextension 38-40 of cab 30 to the outer ends of pivot shaft 36. Cab 30will then be rotated forwardly around the axis of pivot shaft 36simultaneously with raising of elevator 24. Thus, upon actuation bothmembers, elevator 24 and cab 30, are rotatably moved in an approachingdirection towards each other as pivot shaft 36 is rotated by lever 54and associated rod 60, the second lever 64 which is likewise attached topivot shaft 36 will be angularly advanced the same distance incorrespondence with the rotating movement of lever 54. Angular rotatingmovement of lever 64 causes the rods 70-72 to be longitudinallydisplaced through rear pivot block 74 to thereby move the front pivotblock 66 into abutment against the free ends of springs 8284. Continuingangular displacement of lever 64 by further upward movement of theelevator 24 results in compression springs 82-84 between opposite pivotblocks 66 and 74 to effectively dampen the downward movement of cab 30onto the raising elevator 24 to thereby prevent the cab against freefalling and eliminate impact shock loads upon engage-ment of the cab 30with the elevator 24.

Maximum upward movement of elevator 24 conjointly with pivotal downwardmovement of cab 30 ultimately results in complete com-pression ofsprings 82-84 substantially at a point A1, just prior to full supportingengagement of cab 30 upon the elevator 24.

After full compression of springs 82-84 at point Al, final upwardmovement of elevator 24 cause the springs 82-84 to be moved, throughdead center, indicated by line DC, towards point A2. The dead center ofthe compression spring assembly of the present improved mechanism isdefined by a line DC drawn through the axes of pivot shaft 36 andtrunnions 76-78. In this position cab 30 is fully engaged upon elevator24 to be supported thereby.

With reference back to FIG. 1 and 2, preferably antifriction means suchas rollers 86 are provided between the front end 32 of the cab 30 andthe top of elevator 24 to permit sliding rolling, engagement of the cabupon the supporting elevator 24. Conveniently, rollers 86 are attachedto the top of elevator 24 and preferably comprise a spaced pair ofrollers for engagement against opposite side edges along the front 32 ofcap 30 as shown in FIG. 2.

Compression springs 82-84 of the present invention comprise an energyloading device which upon full compression of the spring and being atthe position A2 beyond dead center DC in FIG. 3 tend to expand at apredetermined force magnitude in counterclockwise direction againstlever 64 to thereby exert a constant rotating force on pivot shaft 36.By this action the tilted cab 30 is effectively clamped down upon thesupporting elevator 24 and securely held in clamped down position bycontinuous expansion force of the compressed springs 82-84 so as toprevent the tilted cab from shaking and rattling upon its supportingmember 24 during transport of the machine over the road or rail. By thisarrangement, which is a subsequent function of the present improvedcompression spring load supporting and shock absorbing assembly, noadditional clamp-down means need to be employed to securely retain thecab 30 in tilted position upon the supporting elevator 24. This providesa considerable saving of material cost and labor.

As will be noted from the foregoing, the shock load damping andclampdown function of the present improved device is completelyautomatic and self-acting in response to the respective rotated positionof pivot shaft 36.

With reference again to FIG. 2, the cab 30 in the forwardly tiltedposition upon the raised support elevator 24, reduces the former overallheight H, as indicated by the respective reference lines in FIG. 1 and2, by a substantial distance H2" indicated at the left FIG. 2. Thisposition in many instances may already be sufficient to provide safeclearance for transport of the machine l0 underneath overpasses orthrough tunnels. However, if further height reduction is necessary, theactuating rod 60 may be detached from elevator 24. Thereafter elevator24 can be further lowered taking the cab 30 with it which is maintainedin rigid supporting engagement with elevator 24 by means of the combinedexpansion force of springs 82-84 acting on lever 64 from the position A2in FIG. 3 to rotate pivot shaft 36 counterclockwise, i.e., in directionof downward movement of the cab 30.

In order to return cab 30 to its normal upright position in FIG. I,elevator 24 is raised upwardly to the point of reattachment of actuatorrod 60 to elevator 24. Further upward movement of elevator 24 causescompression springs 82-84 to be moved past dead center DC in returndirection from point A2 to a point A1 at which the expansion force ofsprings 82-84 now exert a force in clockwise direction upon lever 64 toaid in returning the cab 30 to its normal upright position shown in FIG.1.

It will be obvious from the foregoing description in connection with theappended drawings that the present improved tilt cab mechanism providesa multifunctional device which is completely self-acting to provide(first) a load supporting and shock adsorbing means on the way down;(secondly) a hold-down means after engagement of the tilted cab upon thesupport and; (thirdly) a cab return means upon return movement of thecab to its normal position.

Although the present invention has been described by means of apreferred embodiment it would be obvious to the person skilled in theart to make various changes and modifications in detail and arrangementwithout departing from the spirit and essential characteristic of theinvention as defined by the scope of the appended claims.

What is claimed is:

1. In combination with a vehicle having a chassis including an operatorstation and a tilting cab normally enclosing said operator station andpivotally movable between a normal enclosing position and a transportposition remote from said operator station; characterized by firstsupport means for said tilt cab associated with said vehicle andpivotally attached to said chassis for movement between a lowered and araised position; a pivot shaft supported for rotation on said chassisfor connection of said tilt cab to said chassis; a first lever attachedto said pivot shaft; a second lever attached to said pivot shaft inangular offset position relative to said first lever; linkage meansbetween said first lever and said first support means; second supportmeans for said tilt cab attached to aid chassis; means operativelyconnecting said second support means with said second lever; actuatormeans for raising of said first support means towards said tilting cab;said second support means comprising an energy storing and loadsupporting device; said first support means upon actuation by saidactuator means being effective to rotate said pivot shaft by means ofsaid first lever and said linkage means to tilt said cab forwardlytowards said first support means and simultaneously activated saidsecond support means by means of said second lever connected to saidpivot shaft whereby said energy storing and load supporting device ofsaid second support means is effective to maintain said tilt cab insubstantially rigid rest position upon said first support means.

2. The combination as defined in claim 1, characterized by provision ofanti-friction means for support of said tilt cab upon said first supportmeans.

3. The combination as defined in claim 1, further characterized by apivot block attached to said chassis rearwardly of said pivot shaft;said means connecting said second support means with said second levercomprising a rod pivotally attached to said lever and slidinglysupported within said pivot block; said energy storing and loadsupporting device of said second support means comprising spring meansassociated with said rod; the axis of said pivot shaft and said pivotblock defining a dead center; said spring means being normally inunloaded condition with said cab is in normal enclosing position wherebyupon actuation of said first support means said spring means will begradually compressed and moved through said dead center to thereby exerta downward clamping force of predetermined magnitude on said cab tomaintain substantially rigid engagement between said first support meansand said cab.

4. In a vehicle, a frame, a tilt cab mounted for tilting movementthereon; cab tilting means connected to said frame and said cab formovement of said cab between a raised and a lowered position;characterized by load absorbing energy storing means; actuator means foractuating said tilting means and said load absorbing energy storingmeans; said load absorbing energy storing means including an overcenterlinkage and at least one spring operatively connected between said caband said frame so that upon activation of said tilting means said cabwill be caused to tilt to said lowered position and said load absorbingenergy storing means will first absorb load during movement of said cabtowards said lowered position and thereafter will exert said load onsaid cab to maintain said cab in said lowered position.

5. The tilt cab mechanism of claim 4 characterized by said cab tiltingmeans comprising a support member mounted for pivotal movement towardssaid cab as the latter tilts towards said lowered position forsupporting engagement with said cab in said lowered position.

6. The tilt cab mechanism of claim 5 characterized in that said vehiclecomprises a combine and said cab tilting means comprises an elevator.

1. In combination with a vehicle having a chassis including an operatorstation and a tilting cab normally enclosing said operator station andpivotally movable between a normal enclosing position and a transportposition remote from said operator station; characterized by firstsupport means for said tilt cab associated with said vehicle andpivotally attached to said chassis for movement between a lowered and araised position; a pivot shaft supported for rotation on said chassisfor connection of said tilt cab to said chassis; a first lever attachedto said pivot shaft; a second lever attached to said pivot shaft inangular offset position relative to said first lever; linkage meansbetween said first lever and said first support means; second supportmeans for said tilt cab attached to aid chassis; means operativelyconnecting said second support means with said second lever; actuatormeans for raising of said first support means towards said tilting cab;said second support means comprising an energy storing and loadsupporting device; said first support means upon actuation by saidactuator means being effective to rotate said pivot shaft by means ofsaid first lever and said linkage means to tilt said cab forwardlytowards said first support means and simultaneously activated saidsecond support means by means of said second lever connected to saidpivot shaft whereby said energy storing and load supporting device ofsaid second support means is effective to maintain said tilt cab insubstantially rigid rest position upon said first support means.
 2. Thecombination as defined in claim 1, characterized by provision ofanti-friction means for support of said tilt cab upon said first supportmeans.
 3. The combination as defined in claim 1, further characterizedby a pivot block attached to said chassis rearwardly of said pivotshaft; said means connecting said second support means with said secondlever comprising a rod pivotally attached to said lever and slidinglysupported within said pivot block; said energy storing and loadsupporting device of said second support means comprising spring meansassociated with said rod; the axis of said pivot shaft and said pivotblock defining a dead center; said spring means being normally inunloaded condition with said cab is in normal enclosing position wherebyupon actuation of said first support means said spring means will begradually compressed and moved through said dead center to thereby exerta downward clamping force of predetermined magnitude on said cab tomaintain substantially rigid engagement between said first support meansand said cab.
 4. In a vehicle, a frame, a tilt cab mounted for tiltingmovement thereon; cab tilting means connected to said frame and said cabfor movement of said cab between a raised and a lowered position;characterized by load absorbing energy storing means; actuator means foractuating said tilting means and said load absorbing energy storingmeans; said load absorbing energy storing means including an overcenterlinkage and at least one spring operatively connected between said caband said frame so that upon activation of said tilting means said cabwill be caused to tilt to said lowered position and said load absorbingenergy storing means will first absorb load during movement of said cabtowards said lowered position and thereafter will exert said load onsaid cab to maintain said cab in said lowered position.
 5. The tilt cabmechanism of claim 4 characterized by said cab tilting means comprisinga support member mounted for pivotal movement towards said cab as thelatter tilts towards said lowered position for supporting engagementwith said cab in said lowered position.
 6. The tilt cab mechanism ofclaim 5 characterizEd in that said vehicle comprises a combine and saidcab tilting means comprises an elevator.